noun
Refers to a school or university club focused on mountaineering and hiking.
彼は高校で山岳部に入った。
He joined the mountaineering club in high school.
noun
mountain area; mountainous region
A somewhat formal or literary term for a mountainous area; in everyday speech, 山間部 or 山地 is more common.
その山岳部では珍しい植物が見られる。
Rare plants can be found in that mountainous area.
Also means mountaineering club, but 山岳部 is the more established term in many schools.
Compound of 山岳 (mountain) + 部 (club, section, or area). The derivation is straightforward from the kanji meanings.